We jumped inside a Mercedes F800 last week—the car that will offer three flavors of fuel as soon as 2012. Mercedes says that the future is a three-lane highway, with cars running on gas, electricity, and hydrogen.

The F800 hybrid will combine a traditional gasoline engine using direct-injection technology with a hybrid module, which can be powered up by simply plugging into a charging station. Hopefully some more of these will be built by the time this prototype hits the road—when was the last time you clapped eyes on a streetside charging station?

Meanwhile, the F-cell variant will run on hydrogen stored in tanks under the seats for electric driving with zero local emissions. The only emission, in fact, is pure water vapor.

As well as prophesying the three-lane philosophy, the F800 is in many ways the sculpted shape of things to come from German marque. It's essentially a three-liter sedan, like its predecessor the F700, but has streamlined sportscar aesthetics with a coupe-like roof and rear doors that slide open, allowing passengers to leap out like less-graceful members of the A-Team.

We can thank the new head of design at Mercedes-Benz, Gorden Wagener, for the chiseled good looks of the F800, which he described as "cultivated sportiness" at a recent preview day in London.

It's actually longer and wider than your average upper-end sedan, in order to accommodate the two alternative engine configurations, but innovations inside the car have kept the weight down. The seats are covered in real wood and perforated leather, but they cover a very minimal lightweight plastic skeleton. The floor of the car is now a single piece of metal rather than the heavy—and costly—sandwich design.

We're not expecting to see the plug-in hybrid edition of the F800 in showrooms before 2012 and probably later for the F-cell edition. Prices are likely to start at around £30,000 ($43,000) for the hybrid and even more for the F-cell, Mercedes warned. But if the F800 Style proves one thing, it's that you can care about the environment and still drive a big fat Merc to work every day. [Mercedes]